* Cash Maple holds 3.5 tln cubic feet of gas
* PTTEP looking to focus on Southeast Asia, Middle East (Adds company comments, context; paragraphs 4-8)
MELBOURNE, Sept 11 (Reuters) - Thailand's PTTEP PTTEP.BK said on Wednesday it was looking to sell down stakes in petroleum exploration permits in Australia, including the Cash Maple gas project, as it shifts focus to investment in Southeast Asia and the Middle East.
PTT Exploration and Production PCL owns 100% of the Cash Maple project off northwestern Australia, which holds a gas resource of 3.5 trillion cubic feet.
"PTTEP is looking at risk-reward sharing opportunities in Cash Maple and other exploration permits in Australia," a PTTEP spokesman said in emailed comments.
"This follows the company's portfolio rationalisation strategy as our focus shifts to investment in our strategic areas, including South East Asia and the Middle East."
PTTEP declined to specify what stake it wanted to sell, give a timeframe or confirm if it was being advised by Miro Capital, as the Australian Financial Review reported this week.
Miro Capital declined to comment.
Cash Maple has long been seen as a potential source of gas supply for the Darwin LNG plant, operated by ConocoPhillips (NYSE:COP) COP.N , after its current source runs out.
However two other gas fields, Barossa and Evans Shoal, are considered more likely to go into Darwin LNG within the next five years.